20 - 30 minuten
Phone was dying spontaneously, after changing battery it works great.
Make sure you pay attention to the guide, and check out a few youtube videos for additional help. Prying battery out was difficult and cracked one of my tools that came with the set. Also the screw driver did not fit any of the screws, I had to use my own. But the battery works well
Keep track of the screws you remove and remember how to put it back together.